Bioactivities of Chitosan and Its Derivatives - Chitosan Based Hydrogels: Functions and Applications - page 169

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Figure 3.32
Inhibitory effect of paclitaxel-incorporated chitosan hydrogel on lewis lung cancer cell (3LL)-tumor growth.
Tumor cells were implanted into the dorsal subcutis of mice. After tumors reached a measurable size (about 100
mm 3 ), 200 mL of paclitaxel-incorporated chitosan hydrogel was administered beneath the tumor. Data were
compared with the average tumor volume of the phosphate-buffered saline (PBS)-treated group on day 12
defined as 100%. Solid circles, paclitaxel and chitosan hydrogel; open circles, chitosan hydrogel alone; triangles,
paclitaxel alone; squares, saline (control). * P < 0.05, paclitaxel and chitosan hydrogel versus the other three
groups. (Adapted from Obara, K. 2005. J control Release 110: 79-89.)

hydrogel incorporating paclitaxel significantly inhibited angiogenesis in tumors.
Application of chitosan hydrogel alone showed an intermediate effect of antiangiogenesis.
It is thus proposed that chitosan hydrogel incorporating paclitaxel may be a promising
new biomaterial to strongly inhibit vascularization and tumor growth.
It should also be noted that application of the chitosan hydrogel alone significantly
inhibited tumor growth, although the inhibitory activity was lower than for the chitosan
hydrogel incorporating paclitaxel. Chitosan has shown a growth-inhibition effect on tumor
cells [245] and inhibition of tumor-induced angiogenesis and tumor metastasis [246].
Chitosan directly inhibits tumor cell proliferation by inducing apoptosis [247].

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Figure 3.33
Effect of paclitaxel-incorporated chitosan hydrogel on 3LL-tumor vascularization. Vascularization of the
3LL tumor, evaluated immunohistochemically with antimurine CD34, markedly decreased in paclitaxel-
incorporated chitosan hydrogel-treated 3LL tumors and chitosan hydrogel-treated 3LL tumors when compared
with paclitaxel-treated and PBS-treated 3LL tumors. * p < 0.05.